CNPS home website

Phytophthora resources

and "CNPS Nurseries & Friends" private web (via left menu, if you are a nursery member)

committee outreach - site visit and consult

On December 5, 2015, the California Native Plant Society adopted a policy on preventing infection and spread of harmful pathogens via native plant nurseries, chapter plant sales, and other growers. The intent is to foster the use of clean native plant stock in all landscape and restoration plantings. The policy calls on CNPS to educate chapters and the public about the plant pathogen problem.

The following resources are primarily intended as guidance to CNPS Chapters that hold chapter plant sales, and to inform CNPS staff and members in their collaborative efforts with others. Any comments on these resources are welcomed and can be sent to Steven Goetz, facilitator for the Committee, at sgoet@sbcglobal.net

GRANTS FOR CNPS CHAPTER NURSERIES

Grants are available from CNPS to upgrade CNPS Chapter Nurseries to comply with Best Management Practices to minimize pathogens in container plants. Grant Applications can be submitted at any time. The first step to apply for these funds is to schedule a site visit by contacting nurserygrants@cnps.org. The Grant Application Guide is here. The spreadsheet for the Project Checklist is here. A table describing the status of the grant applications received from CNPS Chapters can be found here.

GUIDANCE FOR BUYING HEALTHY CONTAINER PLANTS

CNPS Chapters that don't have nurseries buy the plants they sell at native plant sales. The Ad Hoc Phytophthora Committee requested the assistance of the Work Group on Phytophthoras in Native Habitats to develop guidance for chapters to help minimize their risk of purchasing contaminated container plants. The Work Group is a coalition of nursery managers, public agencies, researchers and non-profit organizations that works on actions to minimize the spread of Phytophthora pathogens in habitat restoration sites and in restoration plant materials. With their help, guidance is now available with the pamphlet: Buying Healthy Plants: What to Look for in a Nursery. This pamphlet describes the potential entry points for contamination in a nursery and suggests questions that Chapters can use to begin a conversation with their grower on the quality of the plants they want to purchase. The pamphlet is here.

Start Here - Frequently Asked Questions about controlling the spread of Phytophthora species in native plant nursery stock. 02 December 20 2016 - These FAQs are meant as a preface to this body of work on
Phytophthora.VIEW

Overview - Phytophthora Species in Native Plant Nursery Stock: Issues and Implications 10 April 2016 - This introductory document presents the problem of Phytophthora species, how plant nurseries can be a source of the pathogen, difficulty with detection, wildland infection and spread, and a systems approach to clean plant production. VIEW
| DOWNLOAD

CNPS Best Management Practices (BMPs) for Producing Clean Nursery Stock. 9 April 2016- This
document contains best management practices (BMPs) recommended for CNPS
Chapters that hold Chapter plant sales. CNPS supports the use of these
BMPs by nurseries that provide plants for Chapter plant sales to
minimize these threats. VIEW | DOWNLOAD

Phytosanitary Procedures for CNPS BMPs for Producing Clean Nursery Stock
5 April 2016 - This document provide descriptions and details of phytosanitary procedures referenced in the CNPS BEST MANAGEMENT PRACTICES (BMPs) FOR PRODUCING CLEAN NURSERY STOCK. Note that alternative methods may be acceptable if they are supported by published data or other valid test results showing that the methods are effective. VIEW | DOWNLOAD

Phytophthora Testing Procedures for CNPS BMPs for Producing Clean Nursery Stock. 7 April 2016- This document provide descriptions and details of Phytophthora testing procedures referenced in the CNPS BEST MANAGEMENT PRACTICES (BMPS) FOR PRODUCING CLEAN NURSERY STOCK. Note that some of the methods are still being tested to determine limits of sensitivity, and additional tests are under development. Very few of the methods in use have been compared side by side for sensitivity to a range of Phytophthora species. VIEW | DOWNLOAD

Evaluating Buy-in Material for Phytophthora. 21 February 2016- This document presents the concept that clean plant stock, free of Phytophthora, is one of the foundations of a clean nursery production system. Phytophthora species can easily be introduced into your nursery if you mix infected nursery stock from other sources (buy-in material) into your clean production area. Discusses methods to evaluate plant stock obtained from other sources. VIEW | DOWNLOAD

Plant Nursery Conditions Favor Phytophthora Root Rots. 21 February 2016- To understand why Phytophthora species are so common in nurseries, we need to understand how plant diseases develop and spread, the disease cycle of Phytophthora root rots, and how nursery conditions relate to these. This document discusses the plant disease triangle and presents the Phytophthora life cycle. VIEW | DOWNLOAD

How Using Fungicides in Nurseries Can Increase the Risk of Moving Phytophthora to Planting Sites. 21 February 2016- This document discusses the problems with fungicide use in the nursery, which suppress disease symptoms but do not eliminate the pathogen. Fungicide use can also interfere with Phytophthora detection tests, resulting in false negatives. Once container stock is no longer treated with fungicides (such as after out planting), the pathogens can spread to other stock and into the environment.
VIEW | DOWNLOAD

Resources from the Working Group on Phytophthora in Native Habitats. The Ad Hoc Committee partners with the Working Group on addressing Phytophthora risks to restoration sites and wildlands. The Working Group was formed in March 2015, with the assistance of the U.C. Cooperative Extension Program, as a voluntary
coalition of native plant nursery managers, land management agencies, researchers, and non-profit
organizations. Their primary purpose is to coordinate a comprehensive, unified program of management,
monitoring, research, education and policy to minimize the spread of Phytophthora pathogens in
restoration sites and native plant nurseries. The Working Group sponsors seminars and workshops for outreach. Resources developed by the Working Group can be found on their website calphytos.org